from what i recall...i have only heard stories about people with 87-88 T2's hitting fuel cut...

if you own a series 5......have you honestly ever experienced fuel cut with it???

 

The 89-91s do have an overboost fuel cut, it's just higher than the S4s'. If you've got a good o-scope and a power supply, you can check it yourself. Supply voltage to the correct pin in the ECU input from the pressure sensor as the car runs, and watch the duty cycle of one of the injectors. Around 3.5V (IIRC) the duty cycle will drop to 0.

Brandon

 

thanks for the reply man...

anyone else every truely experience it in their S5?

 

My car did it when I first bought it unmodified. (1990 Turbo II)

 

I constantly hit 10 psi in my '89 TII and never experienced fuel cut.

 

Yeap...I experienced fuel cut ('90 TII) when I was boosting to around 8 psi. Since then, I have the FCD and fuel cut is gone, even when the turbo spiked to 13 psi. Jay

 

some people say they don't. if your lucky I guess some ECU's don't or have higher ratings. I know my friend did in his 90 tII. I put my FCD on as soon as I put my exhaust on so I've never tried.

boosting fc, are you running an FCD? because the g-force gets rid of that right?

 

I hit fuel cut on mine yesterday. 8K. Racing a '78 930 turbo!

 

The G-Force that I am running was only programmed for dp, intake and cat-back (and stock turbo so you don't want to go higher than 10 psi anyways), so they set the fuel cut to ~11 psi (moving fuel cut point from 8 to 11 psi), but my upgraded turbo can boost much higher. At 11 psi, the G-Force forces a fuel cut. Hence, I also run an FCD as well when I drag race my friends. Otherwise, I "normally" run my car at only 8-9 psi.

Jay

 

No fuel cut on my '89 TII....I've seen 12-15psi. I thouht my guage was just nt accurate, but I've since found out it is, so I guess I don't have any fuel cut

 

I've read in a few places fuel cut for all FC's is 8.6psi.

 

Oh wait. We are talking abotu fuel cut from boost? ahhhh. NM then. I never have hit fuel cut from boost.

What I meant was "rev limiter".

 

hehe...yeah i just meant fuel cut...so that could possibly hit it even at 4K rpms if you build enough boost by that time.


Chance: is that 10psi AFTER you put in your FCD?

 

i only hitted fuel cut twice when i was boosting around 9 psi in 5th gear

never happened in other gears

 

Oh. I was getting fuel cut b/c my wiring was messed up. Started @ 6 PSI. Hmm. I corrected the problem. I haven't gotten fuel cut yet. 9.5 PSI and no cut. I have a plug in Racing beat FCD. I think you should see fuel cut up around 11-14 PSI. It all depends how your Computer is going to act and when to cut out the secondaries. Anything over 10 PSI calls for a programmable onboard computer.